package top.zhdev.community.service.impl;

import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.connection.RedisStringCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import top.zhdev.community.service.DataService;
import top.zhdev.community.utils.RedisKeyUtil;

import javax.annotation.Resource;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

/**
 * 数据统计处理器
 */
@Service
public class DataServiceImpl implements DataService {


    @Resource
    private RedisTemplate redisTemplate;

    private SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");

    // 将指定ip计入uv
    @Override
    public void recordUV(String ip) {
        String redisKey = RedisKeyUtil.getUVKey(df.format(new Date()));
        redisTemplate.opsForHyperLogLog().add(redisKey,ip);
    }

    @Override
    public void recordDAU(Integer userId) {
        String redisKey = RedisKeyUtil.getDAUKey(df.format(new Date()));
        redisTemplate.opsForValue().setBit(redisKey,userId,true);
    }

    // 统计指定日期范围内的uv
    public long calculateUV(Date start,Date end){
        if(start == null || end == null){
            throw new IllegalArgumentException("参数不能为空");
        }
        // 整理该日期范围内的key
        List<String> keyList = new ArrayList<>();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(start);
        while(! calendar.getTime().after(end)){
            String key = RedisKeyUtil.getUVKey(df.format(calendar.getTime()));
            keyList.add(key);
        }

        // 合并这些日期内的数据
        String redisKey = RedisKeyUtil.getUVKey(df.format(start),df.format(end));
        redisTemplate.opsForHyperLogLog().union(redisKey,keyList.toArray());

        // 返回统计后的结果
        return  redisTemplate.opsForHyperLogLog().size(redisKey);
    }

    // 统计指定日期范围内的DAU
    @Override
    public long calculateDAU(Date start, Date end) {
        if(start == null || end == null){
            throw new IllegalArgumentException("参数不能为空");
        }

        // 整理该日期范围内的key
        List<byte[]> keyList = new ArrayList<>();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(start);
        while (!calendar.getTime().after(end)) {
            String key = RedisKeyUtil.getDAUKey(df.format(calendar.getTime()));
            keyList.add(key.getBytes());
            calendar.add(Calendar.DATE, 1);
        }

        // 进行OR 运算
        return (long) redisTemplate.execute(new RedisCallback() {
            @Override
            public Object doInRedis(RedisConnection connection) throws DataAccessException {
                String redisKey = RedisKeyUtil.getDAUKey(df.format(start), df.format(end));
                connection.bitOp(RedisStringCommands.BitOperation.OR,
                        redisKey.getBytes(), keyList.toArray(new byte[0][0]));
                return connection.bitCount(redisKey.getBytes());
            }
        });
    }
}
